In reply to ChrisBrooke:
Chris, Glad you like the look of the product.
The walls are made from exterior grade plywood, with no timber at all. We recommend treating with a water based wood preservative and varnishing to get maximum life outdoors - which is a service we can offer - but is excluded from the standard product to keep the product as affordable as possible. We can also offer a full stainless steel fixing set, but this is non-standard for the same reason.
We are shortly going to be launching some other elements of the system, including shelters to protect the wall and climber from rain, snow or sun. Please keep an eye on our socials and site for release soon.
Thanks, Team Interface